Boost controller provides a total of 4 outputs, including 2 high-voltage 2.5A channels and 1.8A low-voltage channels.

Analog Devices announced the release of the new Power by Linear™ LT8603, a quad-output monolithic switching regulator capable of 42V input. The new product integrates one boost controller, two high-voltage 2.5A and 1.5A synchronous step-down channels, and one low-voltage 1.8A synchronous step-down channel, enabling a total of four independent outputs.

The LT8603 can be configured as a boost controller to provide input to a buck converter, thereby supplying three voltages. This is useful when the input drops significantly below a controlled output voltage. For example, in automotive cold crank or start-stop situations, the battery voltage can drop as low as 3V, but by configuring it differently and driving the boost controller as one of the step-down outputs, four precisely controlled outputs can be applied within a compact solution footprint.

The LT8603's triple-buck synchronous rectification topology provides up to 93% efficiency, and burst mode operation maintains a standby current of less than 28µA (high-voltage channel enabled) in no-load standby state, making it ideal for always-on systems. For noise-sensitive applications, the LT8603 has low EMI emissions and meets CISPR 25, Class 5 EMI requirements even at a switching frequency of 2MHz. The switching frequency of the LT8603 can be set between 250 kHz and 2.2 MHz, and can be synchronized within that frequency range.



The LT8603 features a low minimum on-time of 85ns (max) and supports cascading topologies, enabling step-down conversion from 16 VIN to 0.8V OUT even at a switching frequency of 2 MHz. These characteristics allow designers to avoid noise-sensitive critical frequency bands, such as AM radio, and utilize a very compact solution footprint. With a wide input voltage range of 3V to 42V, it is suitable for automotive applications where regulation is essential in cold-crank and stop-start situations involving load dump transient voltages exceeding 40V and minimum input voltages as low as around 3V. Programmable power-on resets and power-good indicators on each channel ensure overall system reliability. The LT8603's 40-pin thermally enhanced 6mm x 6mm QFN package and high switching frequency allow for small external inductors and capacitors, providing a compact and thermally efficient footprint.